External reflection studies of CO on platinized platinum electrodes

Journal Article · Mon Jun 01 04:00:00 EDT 1998 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.55742· OSTI ID:21185696

Bjerke, Amy E; Griffiths, Peter R ^[1]

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1. Department of Chemistry, University of Idaho, Moscow, Idaho 83844-2343 (United States)

Several studies have shown a difference in the electrochemical response of bare platinum vs platinized platinum electrodes. We have found that the thickness of the platinum black coverage on a Pt electrode also changes the spectroscopic response of CO adsorbed on such a surface. A polycrystalline electrode was platinized at 2.75 V in a solution of chloroplatinic acid/lead acetate for time periods of 10 to 30 s. External reflection spectra were calculated using a single-beam spectrum collected with a monolayer of CO on the electrode and a single beam spectrum without the adsorbed CO as a reference. At lower platinization times, the CO peak existed as the expected upward-going band. As the platinization time was increased, the band shape became dispersive and the intensity of the band increased. At the highest platinization time, the peak appeared to invert itself into a downward going band, i.e., the reflection increased in the region of the CO absorption. This surprising phenomenon appears to be directly related to the change in the surface features with increased platinization time.

• OSTI ID: 21185696
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 430; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ADSORPTION
CARBON MONOXIDE
CHEMISORPTION
ELECTROCHEMISTRY
ELECTRODES
PLATINUM
POLYCRYSTALS
REFLECTION
REFLECTIVITY
SCANNING ELECTRON MICROSCOPY
SPECTRAL REFLECTANCE
SURFACES